1. Field of the Invention
The present invention is applicable to a variety of educational, game, amusement and graphic arts products and devices. More particularly, it relates to a new system of visual communication wherein a paper or similar substrate is provided with a marking surface having at least one area intended to be marked by the user to produce a first visible indicium in response to a question, instruction or other stimuli. As a result of this response, a second visible indicium is automatically and promptly generated in that area. This second indicium visually communicates to the user and others knowledge as to the correctness or value of his response, or pleasure in seeing an unexpected or aesthetically pleasing change in the area marked.
2. Description of the Prior Art
Referring first to the educational field, many proposals have been advanced in the past for the use of invisible ink or concealed printing in preparing auto-corrective tests, programed teaching courses, and other similar instructinal devices intended to provide feedback to the student and teacher. In this context, the term "feedback" is defined as a transfer of information from the instructional device to the student and/or teacher after a response has been made by the student. Such prior proposals usually have required development of the invisible ink or revelation of the concealed printing through a chemical, electrical or mechanical reaction between a device operated by the student and the information concealed on the paper. The following United States Patents disclose systems representative of such prior proposals: U.S. Pat. Nos. 3,826,499; 3,701,205; 3,632,364; 3,788,863; 3,677,786; 3,438,927; 3,745,672; 3,638,335; 3,363,338; 2,420,336. At best, these proposals have met with very limited success. One of the major difficulties involved in using an invisible ink is in applying it in such manner that it truly is invisible. Otherwise, one who is taking a test, or the like, may quickly discover slight visual clues as to location of the ink and thereafter depend upon such clues in responding to a question or instruction.
Another problem with many invisible inks resides in the difficult or inconvenient procedures involved in developing them to a visible state. For instance, some systems require acids or special lights that are not readily available to the average user. Others require the application of water as by dipping, wiping or spraying, thereby producing a wet sheet which is difficult and messy to handle. Still others require the use of special developer fluids and/or applicators which are not readily available, which present problems of toxicity, or which are impractical because they have no real utility except as developers.
As a result of such problems with invisible inks, various proposals have been advanced for using concealed printing. For instance, systems have been devised incorporating water soluble dyes in printing inks, the dyes dissolving to provide a color response upon being contacted by a water filled pen or brush. Other proposed systems have involved an overlay which is erased or scraped away to reveal the preprinted answer. Here again, however, these proposals have met with little long term success because of such problems as "registry" in making multiple runs of a product through a printing press, high costs, difficulty in use, etc.
Thus, in spite of many development efforts and the expenditure of substantial time and money over the years, the educational field still lacks a truly satisfactory system for selfcorrecting tests and the like which is cheat proof, safe and convenient in use, and efficient and effective yet inexpensive and easily produced.
Turning now to games, puzzles, amusement devices, and the like, this field has experienced many of the same problems as noted above with respect to the educational field. A game or puzzle having answers printed in so-called invisible ink many times will give visible "clues" which can be utilized to win unfairly or gain some advantage. Also, the development of such inks leaves much to be desired as it normally requires a special chemical, applicator or treatment which may not be readily available, dangerous to a young user or messy or inconvenient. For instance, some invisible inks are developed by heat, as by being held over a candle or other heat source. Obviously, such a procedure not only may lead to destruction of the paper on which the invisible message is written, but involves significant danger to the user and adjacent objects in the event of unexpected ignition of the paper.
Also, with particular reference to coloring sets or books of the type used primarily by children, there has been little if any change for a great many years. The usual coloring book consists -- as it has for many years -- of sheets having printed outlines which are simply filled in with wax crayons, a brush dipped in water colors, and the like.
One proposal to improve the usual coloring procedure involves printing "dots" within the area to be colored, using a black printing ink in which water soluble dyes have been suspended. When these "dots" are contacted by a water filled brush or the like, the suspended dyes dissolve and the area is then colored by moving the brush thereover. Because of the lack of any choice or variety in color selection by the user and of very weak "colors" resulting from this process, however, it has met with only limited success.
In considering the general graphic arts field, one of the oldest and most perplexing problems experienced by artists, designers, and others involved in layout work is encountered in attempting to quickly and inexpensively prepare designs, drawings, copy, etc., in what might be called "two color" reverse. For example, preparation of a simple design including vivid green lines on a red background normally would require such complicated and time consuming procedures as
(a) starting with a white sheet, inking in the green lines and then inking in the solid red background,
(b) starting with a sheet having an overall red coating, erasing or otherwise removing the coating from the areas intended to represent the green lines, and then inking or otherwise applying green into these areas, or
(c) starting with a red sheet, carefully cutting out the areas intended to form the green lines, and then either cutting out and inserting the green lines or placing a green sheet beneath the red sheet.
As a result of the difficulty attendant to the preparation of such "two color" reverses, they are seldom used except in cases of extreme urgency. Practically any artist, designer, or other individual involved in layout work, however, would welcome and frequently use a system by which such a "two color" reverse could be inexpensively, and quickly prepared.